Supercharging structure for a fan

ABSTRACT

A fan having a supercharging structure comprises a casing having an air passage hole with an air inlet at a first end thereof and an air outlet at a second end thereof. A base is mounted to the air outlet end of the casing. A supporting plate is mounted in the air passage hole of the casing or an air outlet in the base for engaging with a stator bobbin that pivotally holds a fan wheel to be driven. Plural supercharging plates are mounted between the supporting plate and the base.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a supercharging structure for afan, wherein the thickness of the casing of the fan can be varied inresponse to a change in the height of the fan wheel while providing anairflow driven by the axial flow fan with a relatively high blastpressure on the air outlet side.

[0003] 2. Description of the Related Art

[0004] U.S. Pat. No. 6,244,818 to Chang issued on Jun. 12, 2001discloses a fan guard structure for additional supercharging function.As illustrated in FIG. 1 of the drawings that corresponds to FIG. 2A ofU.S. Pat. No. 6,244,818, the fan guard 90 comprises a motor holder 91and plural radial guard blades 92. A rotor device is mounted to themotor holder 91 and comprises a motor 93 for driving a shaft ring (fanwheel) 94. When the fan wheel 94 turns, surrounding air is introduced bythe rotor blades 95 to generate an airflow which is outputted afterpassing through gaps between the guard blades 92. The blast pressure ischanged from a relatively low value on the air inlet side into arelatively high value on the air outlet side. That is, there is a blastpressure enhancement on the air outlet side.

[0005] As illustrated in FIG. 2 that corresponds to FIG. 7 of U.S. Pat.No. 6,244,818, a composite fan comprises two fan units 90 each includingguard blades 92 and the rotor device mentioned above, which alsofulfills the function of improving performance of the fan.

[0006] The fan disclosed in U.S. Pat. No. 6,244,818 has a fixedthickness (or height), as the thickness of the casing 90 and of the fanwheel 94 is fixed. Thus, factories manufacturing the fans must preparemolds for manufacturing casings 90 of various thicknesses. In addition,spare products are required for different needs.

[0007] Furthermore, mounting of the motor 93, fan wheel 94, and drivecircuit of the rotor device into the casing 90 becomes difficult whenthe casing 90 is relatively thick. Further, inconvenience was found whenmounting the fan disclosed in U.S. Pat. No. 6,244,818 on aheat-dissipating member, which is the most common use of the fan.

SUMMARY OF THE INVENTION

[0008] It is, therefore, an object of the present invention to provide asupercharging structure for a fan, wherein the thickness of the casingof the fan can be varied in response to a change in the fan wheel.

[0009] Another object of the present invention is to provide asupercharging structure for a fan, wherein the rotor device of the fancan be assembled easily.

[0010] A further object of the present invention is to provide asupercharging structure for a fan, wherein the fan can be directlyengaged with a heat-dissipating member to thereby form aheat-dissipating unit.

[0011] A fan having a supercharging structure comprises a casing havingan air passage hole with an air inlet at a first end thereof and an airoutlet at a second end thereof. A base is mounted to the air outlet endof the casing. A supporting plate is mounted in the air passage hole ofthe casing or in an air outlet in the base for engaging with a statorbobbin that pivotally holds a fan wheel to be driven. Pluralsupercharging plates are mounted between the supporting plate and thebase.

[0012] Other objects, specific advantages, and novel features of theinvention will become more apparent from the following detaileddescription and preferable embodiments when taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is an exploded perspective view of a conventional fandisclosed in U.S. Pat. No. 6,244,818.

[0014]FIG. 2 is an exploded perspective view of a conventional compositefan disclosed in U.S. Pat. No. 6,244,818.

[0015]FIG. 3 is an exploded perspective view of a first embodiment ofthe fan in accordance with the present invention.

[0016]FIG. 4 is a sectional view illustrating assembly of the fan inFIG. 3.

[0017]FIG. 5 is a sectional view of the fan in FIG. 3 after assembly.

[0018]FIG. 6 is an exploded perspective view of a second embodiment ofthe fan in accordance with the present invention.

[0019]FIG. 7 is a sectional view illustrating assembly of the fan inFIG. 6.

[0020]FIG. 8 is a sectional view of the fan in FIG. 6 after assembly.

[0021]FIG. 9 is an exploded perspective view of a third embodiment ofthe fan in accordance with the present invention.

[0022]FIG. 10 is a sectional view of the fan in FIG. 9 after assembly.

[0023]FIG. 11 is an exploded perspective view of a fourth embodiment ofthe fan in accordance with the present invention.

[0024]FIG. 12 is a sectional view of the fan in FIG. 11 after assembly.

[0025]FIG. 13 is an exploded perspective view of a fifth embodiment ofthe fan in accordance with the present invention.

[0026]FIG. 14 is an exploded perspective view of a sixth embodiment ofthe fan in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Preferred embodiments in accordance with the present inventionwill now be described with reference to the accompanying drawings.

[0028] Referring to FIG. 3, a first embodiment of the fan in accordancewith the present invention generally comprises a casing 1, a base 2, anda fan wheel 3.

[0029] The casing 1 may be of any desired height and comprise an airpassage hole 11 having an air inlet at an end thereof and an air outletat the other end thereof. The casing 1 includes holes 12 through whichfasteners (such as bolts or the like) extend.

[0030] The base 2 is coupled to the air outlet end of the casing 1 andcomprises engaging members 21 that include hooks for hooking on oppositeedges 13 of the casing 1. In order to prevent exposure of the engagingmembers 21, each edge 13 includes notches or recesses 14 for receivingthe hooks of the engaging members 21 such that the engaging member 21are flush with the edges 13 of the casing 1 after assembly, best shownin FIG. 5. The base 2 further comprises an air outlet 22 aligned withthe air passage hole 11 of the casing 1. An inner wall defining the airoutlet 22 is preferably horn-shaped. A supporting plate 23 is mounted inthe air outlet 22 of the base 2, and plural supercharging plates 24 areconnected between the supporting plate 23 and the base 2, thereby fixingthe supporting plate 23. Each supercharging plate 24 is an inclinedplate or has a shape as that of an axial flow blade. The inclinationdirection of the supercharging plates 24 is opposite to that of blades33 of the fan wheel 3. The supporting plate 23 further comprises an axleseat 25 for engaging with a stator bobbin 31 of the fan wheel 3.Further, holes 26 are defined in the base 2 and aligned with the holes12 of the casing 1.

[0031] The fan wheel 3 comprises a central shaft 32 that is rotatablyreceived in the stator bobbin 31. The blades 33 of the fan wheel 3 maydrive the air to flow. The stator bobbin 31 is engaged on the axle seat25 of the supporting plate 23, as mentioned above.

[0032]FIGS. 4 and 5 illustrate assembly procedure of the fan in FIG. 3.The stator bobbin 31 is mounted to the axle seat 25 of the base 2. Thecentral shaft 32 of the fan wheel 3 is then rotatably mounted in thestator bobbin 31. Next, the base 2 is coupled to the casing 1 by theengaging members 21. Since the fan wheel 3 and the stator bobbin 31 aredirectly mounted on the base 2, the assembly procedure is convenient. Inaddition, the thickness (or height) of the casing 1 can be selectedaccording to the height of the fan wheel 3. When the fan wheel 3 turns,air is driven by the blades 33 and thus sucked into the air inlet of theair passage hole 11 and then exits the base 2 via the air outlet 22 ofthe base 2. The blast pressure of the airflow is increased when exitingthe air outlet 22 due to provision of the inclined supercharging plates24.

[0033] Referring to FIG. 6, a second embodiment of the fan in accordancewith the present invention generally comprises a casing 4, a base 5, anda fan wheel 3.

[0034] The casing 4 comprises an air passage hole 41 having an air inletat an end thereof and an air outlet at the other end thereof. The casing4 includes holes 42 through which fasteners (such as bolts or the like)extend. A supporting plate 45 is supported in the air outlet of the airpassage hole 41 by a rod 44 and comprises an axle tube 46.

[0035] The base 5 is coupled to the air outlet end of the casing 4. Inthis embodiment, the base 5 comprises engaging members 51 that includehooks for hooking on opposite edges 43 of the casing 4 to therebyprovide convenient assembly. The base 5 further comprises an air outlet52 aligned with the air passage hole 41 of the casing 4. A solid centralportion 53 is formed in the air outlet 52 of the base 5, and pluralsupercharging plates 54 are connected between the solid central portion53 and the base 5. Each supercharging plate 54 is an inclined plate orhas a shape as that of an axial flow blade. The inclination direction ofthe supercharging plates 54 is opposite to that of blades 33 of the fanwheel 3. Further, holes 55 are defined in the base 5 and aligned withthe holes 42 of the casing 4.

[0036] The fan wheel 3 comprises a central shaft 32 that is rotatablyreceived in the stator bobbin 31. The blades 33 of the fan wheel 3 maydrive the air to flow. The stator bobbin 31 is engaged on the axle tube46 of the supporting plate 45, as mentioned above.

[0037]FIGS. 7 and 8 illustrate assembly procedure of the fan in FIG. 6.The stator bobbin 31 is mounted to the axle tube 46 of the base 4. Thecentral shaft 32 of the fan wheel 3 is then rotatably mounted in thestator bobbin 31. Next, the base 5 is coupled to the casing 4 by theengaging members 51. Since the fan wheel 3 and the stator bobbin 31 aredirectly mounted on the axle tube 46 of the base 4, the assemblyprocedure is convenient. When the fan wheel 3 turns, air is driven bythe blades 33 and thus sucked into the air inlet of the air passage hole41 and then exits the base 5 via the air outlet 52 of the base 5. Theblast pressure of the airflow is increased when exiting the air outlet52 due to provision of the inclined supercharging plates 54.

[0038]FIGS. 9 and 10 illustrate engagement between the fan in accordancewith the present invention and a heat-dissipating member 6. Fasteners 61(such as bolts or the like) are extended through holes 55 in the base 5and then engaged into the heat-dissipating member 6, thereby securingthe base 5 and the heat-dissipating member 6 together. The engagingmembers 51 of the base 5 are hooked on the edges 43 of the casing 4 forassembly purpose.

[0039]FIGS. 11 and 12 illustrate another engagement between the fan inaccordance with the present invention with a heat-dissipating member 6.Plural legs 56 extend downward from the base 5 and clamp theheat-dissipating member 6. Fasteners 61 (such as bolts or the like) areextended through holes 55 in the legs 56 and then engaged into a board(not shown) on which the heat-dissipating member 6 is mounted, therebysecuring the base 5 and the heat-dissipating member 6 together. Theengaging members 51 of the base 5 are hooked on the edges 43 of thecasing 4 for assembly purpose.

[0040]FIG. 13 illustrates a further engagement between the fan inaccordance with the present invention and a heat-dissipating member 6.Fasteners 61 (such as bolts or the like) are extended through holes 42in the casing 4, holes 55 in the base 5, and holes 62 in theheat-dissipating member 6, thereby securing the casing 4, the base 5,and the heat-dissipating member 6 together. Mounted to the casing 4 is afan wheel 3 that can be driven to turn. The base 5 comprises pluralsupercharging plates 54 for supercharging the airflow when the fan wheel3 turns to thereby provide supercharged airflow, thereby providing theheat-dissipating member 6 with improved heat-dissipating effect.

[0041]FIG. 14 illustrates still another engagement between the fan inaccordance with the present invention and a heat-dissipating member 6.The base 5 is relatively long for providing plural air outlets 52 eachhaving a set of supercharging plates 54 mounted therein. Fasteners 61(such as bolts or the like) are extended through holes 55 in the base 5and engaged into the heat-dissipating member 6 that is longer orthicker, thereby securing the base 5 and the heat-dissipating member 6together. Plural casings 4 are provided, and the base 5 comprisesengaging members 51 for engaging with the casings 4. Mounted to eachcasing 4 is a fan wheel 3 that can be driven to turn. The superchargingplates 54 of the base 5 supercharge the airflow when the fan wheels 3turn to thereby provide supercharged airflow, thereby providing theheat-dissipating member 6 with improved heat-dissipating effect.

[0042] The fan in accordance with the present invention comprises acasing and a base that can be easily coupled to the casing. In addition,the base comprises supercharging plates for the airflow that isgenerated as a result of turning of the fan wheel. In addition, the fanin accordance with the present invention can be conveniently mounted toa heat-dissipating member.

[0043] Although the invention has been explained in relation to itspreferred embodiment as mentioned above, it is to be understood thatmany other possible modifications and variations can be made withoutdeparting from the scope of the invention. It is, therefore,contemplated that the appended claims will cover such modifications andvariations that fall within the true scope of the invention.

What is claimed is:
 1. A fan comprising: a casing comprising an airpassage hole, the air passage hole having an air inlet at a first endthereof and an air outlet at a second end thereof; and a base comprisingplural engaging members for coupling the base to the air outlet end ofthe casing, the base comprising an air outlet, a supporting plate beingmounted in the air outlet of the base, a stator bobbin being mounted tothe supporting plate, a fan wheel being rotatably mounted to the statorbobbin, and plural supercharging plates being mounted between thesupporting plate and the base.
 2. The fan as claimed in claim 1, whereinthe casing comprises two opposite edges, each of the engaging memberscomprising a hook to be hooked on an associated one of the edges of thecasing.
 3. The fan as claimed in claim 2, wherein each said edge of thecasing comprises plural recesses for receiving the engaging members. 4.The fan as claimed in claim 1, wherein an inner wall defining the airoutlet of the base is horn-shaped.
 5. The fan as claimed in claim 1,wherein each said supercharging plate is an inclined plate.
 6. The fanas claimed in claim 1, wherein each said supercharging plate has a shapeas that of an axial flow blade, each said supercharging plate having aninclination direction opposite to that of blades of the fan wheel. 7.The fan as claimed in claim 1, wherein the casing and the base comprisealigned holes through which fasteners extend for securing the casing andthe base together.
 8. The fan as claimed in claim 1, wherein the basecomprises plural legs extending therefrom, said legs being adapted toclamp a heat-dissipating member, each said leg including a hole.
 9. Afan comprising: a casing comprising an air passage hole, the air passagehole having an air inlet at a first end thereof and an air outlet at asecond end thereof, a supporting plate being supported in the airpassage hole, the supporting plate having an axle tube; a stator bobbinmounted to the axle tube of the supporting plate; a fan wheel rotatablymounted to the stator bobbin and comprising plural blades; and a basecomprising plural engaging members for coupling the base to the airoutlet end of the casing, the base comprising an air outlet having acentral portion, and plural supercharging plates being mounted betweenthe central portion and the base.
 10. The fan as claimed in claim 9,further comprising additional said casings each having an air outlet,the base comprising additional said air outlets respectively alignedwith the air outlets of additional said casings.
 11. The fan as claimedin claim 9, wherein the casing comprises two opposite edges, each of theengaging members comprising a hook to be hooked on an associated one ofthe edges of the casing.
 12. The fan as claimed in claim 11, whereineach said edge of the casing comprises plural recesses for receiving theengaging members.
 13. The fan as claimed in claim 9, wherein an innerwall defining the air outlet of the base is horn-shaped.
 14. The fan asclaimed in claim 10, wherein an inner wall defining each of the airoutlets of the base is horn-shaped.
 15. The fan as claimed in claim 9,wherein the casing and the base comprise aligned holes through whichfasteners extend for securing the casing and the base together.
 16. Thefan as claimed in claim 10, wherein the casings and the base comprisealigned holes through which fasteners extend for securing the casingsand the base together.
 17. The fan as claimed in claim 9, wherein thebase comprises plural legs extending therefrom, said legs being adaptedto clamp a heat-dissipating member, each said leg including a hole. 18.The fan as claimed in claim 10, wherein the base comprises plural legsextending therefrom, said legs being adapted to clamp a heat-dissipatingmember, each said leg including a hole.
 19. The fan as claimed in claim9, wherein each said supercharging plate is an inclined plate.
 20. Thefan as claimed in claim 10, wherein each said supercharging plate is aninclined plate.
 21. The fan as claimed in claim 9, wherein each saidsupercharging plate has a shape as that of an axial flow blade, eachsaid supercharging plate having an inclination direction opposite tothat of blades of the fan wheel.
 22. The fan as claimed in claim 10,wherein each said supercharging plate has a shape as that of an axialflow blade, each said supercharging plate having an inclinationdirection opposite to that of blades of the fan wheel.